c# - Codedom 和字符串处理

我对此进行了研究，但找不到任何可靠的东西，想看看是否有人可以指出我正确的方向。我正在尝试查看 Codedom 是否可以处理不同语言之间的字符串和合并，而无需我为每种语言设置条件字符串。

例如，我需要通过 Codedom 在 C# 和 VB.NET 中完全如下所示生成以下内容:

C#

errorMsg = errorMsg.Replace('"', '\'').Replace("\r\n", @"\n");
System.Windows.Browser.HtmlPage.Window.Eval("throw new Error(\"Unhandled Error in Silverlight Application " + errorMsg + "\");");

VB.NET

errorMsg = errorMsg.Replace(""""c, "'"c).Replace(ChrW(13) & ChrW(10), "\n")
System.Windows.Browser.HtmlPage.Window.Eval("throw new Error(""Unhandled Error in Silverlight Application " + errorMsg + """);")

CodeMethodInvokeExpression 和 errorMsg.Replace 的 System.Windows.Browser.HtmlPage.Window.Eval 很简单，就是其中的字符串，我不知道 Codedom 是否可以自动处理。

最佳答案

不幸的是，代码原语在组合时并不总是产生预期的结果，因为提供者会采取一定的自由来解释意图。解决这个问题的方法是使用 CodeSnippetExpression 。

这是用于生成您在问题中列出的 Eval 语句的代码(VB.NET 和 C#)。随意使用最适合您的:

VB.NET 版本

Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Reflection
Imports System.Text
Imports System.IO
Imports Microsoft.CSharp

Public Class PrintEvalStatement
    Public provider As CodeDomProvider

    Sub New()
        Dim left As New CodePrimitiveExpression("throw new Error(""Unhandled Error in Silverlight Application ")
        Dim middle As New CodeVariableReferenceExpression("errorMsg")
        Dim right As New CodePrimitiveExpression(""");")

        Dim targetObject = New CodeTypeReferenceExpression("System.Windows.Browser.HtmlPage.Window")
        Dim methodName = "Eval"

        provider = New VBCodeProvider()
        Dim vbStatement As String = ConcatStatement(left, middle, right, targetObject, methodName)

        provider = New CSharpCodeProvider()
        Dim csStatement As String = ConcatStatement(left, middle, right, targetObject, methodName)

        Console.WriteLine(vbStatement)
        Console.WriteLine(csStatement)
        Console.ReadLine()
    End Sub

    Private Function ConcatStatement(ByVal left As CodePrimitiveExpression,
                                     ByVal middle As CodeVariableReferenceExpression,
                                     ByVal right As CodePrimitiveExpression,
                                     ByVal targetObject As CodeTypeReferenceExpression,
                                     ByVal methodName As String) As String
        Dim evalMessage As New CodeExpression
        evalMessage = ConcatString(left, middle, right)

        Dim eval As New CodeMethodInvokeExpression(targetObject, methodName, evalMessage)
        Dim evalStatement As New CodeExpressionStatement(eval)
        Dim sw As StringWriter = New StringWriter()

        Using tx As TextWriter = New StringWriter()
            provider.GenerateCodeFromStatement(evalStatement, tx, New CodeGeneratorOptions())
            Return tx.ToString()
        End Using
    End Function
    Private Function ConcatString(ByVal left As CodeExpression,
                                  ByVal middle As CodeExpression,
                                  ByVal right As CodeExpression) As CodeExpression
        Return New CodeSnippetExpression(CodeToString(left) + " + " + CodeToString(middle) + " + " + CodeToString(right))
    End Function
    Private Function CodeToString(ByVal expr As CodeExpression) As String
        Using tx As TextWriter = New StringWriter()
            provider.GenerateCodeFromExpression(expr, tx, New CodeGeneratorOptions())
            Return tx.ToString()
        End Using
    End Function


End Class

C# 版本

using System.CodeDom;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Text;
using System.IO;
using Microsoft.CSharp;
using Microsoft.VisualBasic;

namespace CodeDom
{
    class Program
    {
        static CodeDomProvider provider;

        static void Main(string[] args)
        {
            Program shell = new Program();
            provider = new VBCodeProvider();
            CodePrimitiveExpression left = new CodePrimitiveExpression("throw new Error(\"Unhandled Error in Silverlight Application\")");
            CodeVariableReferenceExpression middle = new CodeVariableReferenceExpression("errorMsg");
            CodePrimitiveExpression right = new CodePrimitiveExpression("\");");

            CodeTypeReferenceExpression targetObject = new CodeTypeReferenceExpression("System.Windows.Browser.HtmlPage.Window");
            string methodName = "Eval";

            string vbStatement =  shell.ConcatStatement(left, middle, right, targetObject, methodName);

            provider = new CSharpCodeProvider();

            string csStatement = shell.ConcatStatement(left, middle, right, targetObject, methodName);

            Console.WriteLine(vbStatement);
            Console.WriteLine(csStatement);
            Console.ReadLine();

        }

        public string ConcatStatement(CodePrimitiveExpression left, CodeVariableReferenceExpression middle, CodePrimitiveExpression right, CodeTypeReferenceExpression targetObject, string methodName)
        {
            CodeExpression evalMessage = new CodeExpression();
            evalMessage = ConcatString(left, middle, right);

            CodeMethodInvokeExpression eval = new CodeMethodInvokeExpression(targetObject, methodName, evalMessage);
            CodeExpressionStatement evalStatement = new CodeExpressionStatement(eval);
            using (TextWriter tx = new StringWriter())
            {
                provider.GenerateCodeFromStatement(evalStatement, tx, new CodeGeneratorOptions());
                return tx.ToString();
            }
        }

        private CodeExpression ConcatString(CodeExpression left, CodeExpression middle, CodeExpression right) {
            return new CodeSnippetExpression(CodeToString(left) + " + " + CodeToString(middle) + " + " + CodeToString(right));
        }

        private string CodeToString(CodeExpression expr) {
            using (TextWriter tx = new StringWriter()) {
                provider.GenerateCodeFromExpression(expr,tx, new CodeGeneratorOptions());
                return tx.ToString();
            }
        }
    }
}

关于c# - Codedom 和字符串处理，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/3484205/